Reinforced containers



y 1966 E. F. REPKING 3,261,533

REINFORCED CONTAINERS Filed Jan. 22, 1965 2 sheets-sheet 2 mllmlnmmn dg wt 14 W 48 E 47 I AW ml a I t l i :7 i l (20 M i 22 Mr l ,./22 l' t2, 4/ FIE. 4 as 0'"' Hi Mil} 47 47 25 i L -99 3 L lA/VENTOQ:

H 52 EDWARD E REP/(W6 United States Patent 3,261,533 REINFORCED CONTAINERS Edward F. Repking, St. Louis County, Mo., assignor to Crown Zellerbaeh Corporation, San Francisco, Calif., a corporation of Nevada Filed Jan. 22, 1965, Ser. No. 427,436 7 Claims. (Cl. 229-23) This invention relates to large, heavy-duty, bulk containers constructed of paperboard and suitable for shipping and handling loose granular materials in quantities of several hundred to five thousand pounds per container unit. More particularly the invention relates to large, bulk containers of corrugated fibreboard having tubular wall structures including at least six side panels and separate end caps which are preassembled before placement over the ends of the tubular wall structure to facilitate assembly and filling of the container units.

Heretofore bulk fibreboard containers having more than four side panels have been of a complexity, commensurate with strength and durability requirements, that they were not reasonably adaptable to one man set-up procedures and often required the use of specialized machinery and equipment to effect the erection of the container. In many instances, it is necessary or desirable to provide a fibreboard container for bulk handling and shipping of loose pourable materials such as granular chemicals that is adaptable to simple, economical set-up, handling, and discharging operations without the use of unduly complex, specialized equipment and excessive manual labor.

It is therefore an object of this invention to afford economies in filling, in-transit handling and unloading operations of bulk materials by the provision of a fibreboard shipping container having a tubular wall unit with at least six sides and separate end closures therefor which are preassembled and simply telescoped over the end margins of the wall unit to effect the container assembly.

Another object of the invention is the provision in a large bulk container of a form of end closure having wall flanges adapted to telescopically engage the end margins of the container wall unit, which wall flanges are preassembled in operative relation by simple folding, locking engagement.

A further object of the invention is the provision in a bulk container of a telescoping end closure characterized by a folded interlocking engagement of discrete members affording unusual rigidity and resistance to stresses encountered in shipping and handling bulk quantity units of pourable, granular materials.

A still further object of the invention is to provide a fibreboard container assembly wherein separate parts thereof are sustained by interfolded locking engagement to permit adhesive connection of the parts without delay in the assembly procedure.

Additional objects and advantages of the invention will be apparent in the following description and drawings of an exemplary form of the invention, wherein:

FIGURE 1 is an exploded view in perspective of container elements embodying the invention with the bottom closure assembly being partially erected;

FIGURE 2 is a partial cross section view through line 22 of FIGURE 1;

FIGURE 3 is a perspective view similar to FIGURE 1 with the bottom closure assembly at a further stage of erection just prior to the final flange folding and the top closure assembly shown;

FIGURE 4 is a perspective view of a completely erected container;

FIGURE 5 is an enlarged fragmentary detail view cut away to show the interrelation of the tubular wall structure and end closure assembly; and

FIGURE 6 is a fragmentary sectional view taken on line 6-6 of FIGURE 3.

Patented July 19, 1966 The bulk container as herein dis-closed is formed from corrugated fibreboard or other suitable foldable material and comprises an even numbered group of wall panels foldably connected in upright tubular relation and two piece end closure members which may be substantially similar on the top and bottom ends of the container. The tubularly arranged wall panels, commonly termed sleeves, are preferably arranged in an octagonal cross section arrangement which approaches a cylindrical tube in stress resistance but avoids undue complexity in manufacturing which would result from a greater number of wall panels, although this is optional providing an even number of walls are maintained. Additionally, it is within the purview of the invention to utilize a pair of concentrically arranged inner and outer sleeves for very large containers and heavy weights of materials.

In regard to the end closure assemblies, an end closure panel conforming to the cross sectional area and conformation of the sleeve or outer sleeve, as the case may be, is provided with foldably connected wall flanges about the perimeter thereof. The wall flange arrangement provides alternate single and double thicknesses with extensions of the single thickness flanges confined between the double thickness flanges to lockingly engage the flanges in erected, connected together relation and in right angular relation to the end closure panel. The end closure assemblies additionally include a dual purpose locking-reinforcement pad disposed in flatwise, coextensive relation to the end closure panel with the free side edges thereof substantially abutting the inner faces of the single thickness wall flanges and the outer one of the double thickness flanges. The pad is provided with recesses in alternate side edges adjacent the double thickness wall flanges which recesses engage the end edges of the innermost one of the double thickness wall flanges thereby securing the end closure assembly in erected condition.

In referring particularly to the drawings, it is to be noted that the separate parts comprising the container are each symmetrical in configuration and reference numerals are not applied to each of the repetitive elements, it being understood that like structural elements have like designation wherever they appear.

FIGURE 1 discloses a tubular body or sleeve 20 and a bottom closure assembly 21. A top closure assembly is not shown as this is preferably identical to the bottom closure assembly 21. The sleeve 20 is preferably of octagonal cross section having eight wall panels 22 in foldably connected relation along side edges 23. The

wall panels 22 are further defined by top edge 24 and bottom edge 25. Two adjacent wall panels 22 will be joined by a conventional manufacturers joint such as a stitch flap or glue flap, not shown.

Also in FIGURE 1, the bottom closure assembly 21 comprises an end cap 30 and locking-reinforcing pad 31. The pad 31 is cut-away to show the end cap 30 includes a central end closure panel 32 conforming to the end edges 25 of the sleeve 20. Scores 33 determine the edges of panel 32 and serve as the fold connection, to the alternating single thickness wall flanges 34 and double thickness wall flanges 35. The single thickness flanges are determined, in addition to the edge scores 33, by the opposite free edges 36 and side edge scores 37. These side edge scores 37 further serve as the fold connection of the triangular extensions 38 which are provided with free top edges 39 recessed inwardly from the respective flange edge 36.

Continuing with FIGURE 1, the double thickness wall flanges 35 include an outer flange 40 and inner flange 41 in foldably connected relation by parallel scores 42. The inner flanges 41 has a free edge 45 opposite and parallel to the fold connection 42 and of a diminished extent in comparison to said fold connection.

The locking-reinforcing pad 31 is substantially coextensive with the end closure panel 32. Accordingly the pad edges 43 are disposed adjacent the edge scores 33 allowing only for the scoring allowance permitting the folding of the wall flanges 34 and 35 as shown in the erected portions of FIGURE 1. The pad 31 includes locking recesses 44 in alternating edges 43 thereof which recesses are aligned with the double thickness wall flanges 35 whereby the inner flange diminished edges 45 may lockingly engage in the pad recesses 44 also shown in the erected flange wall portions. Also, the triangular extensions 38 are disposed between the respective adjacent outer and inner flanges 4041 with the recessed top edges 39 thereof abutting the inner surface of the fold connection 42 securely locking the flanges 34 and 35 together and in perpendicular relation to the end closure panel 32. As shown by reference to FIGURES 1 and 3, the folding and erection of the wall flanges 34-35 may proceed consecutively around the assembly and thus may be accomplished manually by a single workman without the use of any extraneous tobls or apparatus.

As represented in FIGURE 2, the end cap 39 is constructed from double faced corrugated board, as well known in the art, comprising two facings or liners and an intervening corrugated member. It may also be constructed of equivalent foldable materials commensurate with the foldability requirements of the double thickness wall panels 35. The locking-reinforcing pad 31 preferably is die-cut from double wall board, also known, having three liner sheets with two corrugated mediums intervening the liners. It is necessary that the corrugations of the end cap 30 and pad 31 are not arranged in parallel relation in order to assure necessary rigidity of the closure assembly 21 in spanning the pallet runners 47. This may be assured by arranging the corrugations in the end cap 30 parallel to an opposed pair of single thickness flanges 34 and the corrugations of the pad 31 parallel to an opposed pair of edges 33 provided with recesses 44. Thus the relative direction of the corrugations in the cap 30 and pad 31 will necessarily be biased and the corrugations of the cap 30 will always be biased to the folds 33 and 45 of the double thickness wall flanges 35 and thereby assure uniform folding and effective locking engagement of the closure assembly 21.

A complete container is shown in FIGURE 4 including a bottom closure assembly 21, a like top closure assembly 48 and a body or sleeve 26. In one commercial usage of the invention, the container successfully accommodates 2,000 pounds of a finely powdered chemical product in shipping and handling. In this instance two sleeves 20 are used, disposed concentrically one with the other, the inner sleeve being termed a liner. In this stage, the container interior dimensions include thirty-nine inches between parallel, opposed wall panels 22 and fifty-eight and one-half inches in height. Also in this usage, the sleeves 20 are 350 pound test double-wall corrugated paperboard, the end caps 30 350 pound test single-wall corrugated board, and the pads 31 500 pound test doublewall corrugated board. The optional pallet runners 47 are multiple ply corrugated with vertically disposed corrugations and having a thickness of about two and onehalf inches. These are adhesively secured to the bottom surface of the bottom closure assembly 21 and are disposed in a non-parallel relation to the corrugations of both the end closure panel 32 and the pad 31. A steel band 48 or the equivalent may be added to afford additional reinforcement to the bottom closure assembly 21. Due to the interlocking, determined disposition of the flanges in the erected assembly 21, this may convenientlying an economy of assembly of the container not heretofore realized in the bulk container art.

FIGURE 5 shows the precise interengagement of the several elements of the container which combine to alford freedom from sifting and unusual strength qualities of the self-locking closure construction. In particular, the locking recess 44 being in the locking-reinforcing pad 31 maintains the end cap closure panel 32 free of openings or lines of weakness which would contribute to possible sifting or failure of the end cap 39. Further the abutting relation of the pad edges 43 against the interior surfaces of the single thickness wall flanges .34 and inner flange 41 of the double thickness wall flanges 35, insures that the sleeve edges 25 will rest upon the margins of the pad 31 and interiorly of the locking recess 44 as the inner flange is infolded over the respective edges 43 of the pad 31 with the end edge 45 thereof engaged in the locking recess as shown in section in FIGURE 6.

The self-locking engagement of the closure assembly 21 flanges 34-455 and locking-reinforcing pad 31 also lends itself to further strengthening the container closure in that adhesive may be applied intervening the pad 31 and panel 32 and also between the interior surfaces of the flanges 34 and 35 and the exterior end margins of the wall panels 22 without delay in the set-up procedure or in filling the container. This result is gained inasmuch as the self-locking construction sustains the container structural elements in position until the adhesive sets thus avoiding the necessity of using extraneous pressure forming apparatus to sustain the container during the adhesive setting period in the conventional manner. The large, heavy duty bulk containers in accordance with this invention are particularly advantageous in packaging situations involving several hundred pounds net weight capacity of granular or powdery flowable materials. Such containers may be characterized as being a size requiring mechanical handling means such as fork lift trucks, conveyors, etc. as they are beyond the reasonable limits of manual handling.

It is to be noted that the description herein and drawings disclose a preferred embodiment of the invention. It is apparent that numerous changes may be made in the construction without departing from the spirit of the invention, and it is therefore desired that the disclosed embodiment be considered as illustrative and not restrictive, reference being had to the appended claims to indicate the scope of the invention.

What is claimed is:

1. A bulk container comprising an upstanding tubular sleeve and a closure assembly disposed in telescoping relation over one end thereof: the tubular sleeve comprising a plurality of foldably connected wall panels including at least three pair of panels in respective opposed, parallel relation and with top and bottom edges; the closure assembly comprising an end cap and locking reinforcing pad; the end cap including a central closure panel coextensive with the tubular sleeve end edge conformation; a plurality of wall flanges, corresponding in number to the sleeve wall panels, and hingedly connected to side edges of the central closure panel; the wall flanges including alternating single and double thickness panels; an extension of the single thickness flanges fixedly sesured between inner and outer plies of the double thickness flange; the reinforcing pad being in flatwise substantially coextensive relation to the end cap central closure panel and having alternate recessed edges adapted to receive free end edges of the double thickness flange inner ply thus securing the reinforcing panel in fixed relation to the end cap central panel and the wall flanges to each other and in right angular relation to the central closure panel.

2. A lbulk container as in claim 1, wherein adhesive is applied between the inner surface of at least one wall flange and the adjacent tubular sleeve wall panel whereby the interlocking, fixed disposition of the closure assembly wall flanges sustain the disposition until the adhesive sets.

3. A bulk container comprising an upstanding tubular sleeve and a closure assembly disposed in telescoping relation over one end thereof: the tubular sleeve comprising a plurality of foldably connected wall panels including at least three pair of panels in respective opposed, parallel relation and with top and bottom edges; the closure assembly comprising an end cap and locking reinforcing pad; the end cap including a central closure panel coextensive with the tubular sleeve end edge conformation; a plurality of wall flanges, corresponding in number to the tubular sleeve wall panels, and hingedly connected to side edges of the central closure panel; the Wall flanges including alternating single and double thickness panels, the respective double thickness panels including inner and outer flange plies with said plies being foldably connected together along their edges opposite to the central closure panel connection; an extension of the single thickness flanges disposed between the respective adjacent inner and outer flange plies with the top edges of the extensions abutting the fold connection therebetween; the reinforcing pad being in flatwise, substantially coextensive relation to the end cap central closure panel and having alternate edges provided with locking recesses; free end edges of the inner flange ply disposed in said locking recesses thus securing the reinforcing panel in fixed relation to the end cap central panel and the wall flanges to each other and in right angular relation to the central closure panel.

4. A heavy duty bulk container for pourable, granular materials, the container being of a size and weight with said material to require mechanical handling means; the tubular sleeve comprising a plurality of foldably connected wall panels including at least three pair of panels in respective opposed, parallel relation and with top and bottom edges; the closure assembly comprising an end cap and reinforcing pad; the end cap including a central closure panel coextensive with the tubular sleeve end edge conformation; a plurality of wall flanges, corresponding in number to the tubular sleeve wall panels, and hingedly connected to side edges of the central closure panel; the Wall flanges including alternating single and double thickness panels, the respective double thickness panels including inner and outer flange plies with said plies being foldably connected together along their edges opposite to the central closure panel connection; an extension of the single thickness flanges disposed between the respective adjacent inner and outer plies With the top edges of the extensions abutting the fold connection therebetween; the reinforcing pad being in flatwise, substantially coextensive relation to the end cap central closure panel and having alternate edges provided with locking recesses; free end edges of the inner flange ply disposed in said locking recesses thus securing the reinforcing panel in fixed relation to the end cap central panel and the wall flanges to each other and in right angular relation to the central closure panel; the end cap being formed from corrugated paperboard with the corrugation aligned in parallel relation to an opposed pair of single thickness wall panels; the reinforcing pad being formed from corrugated paperboard with the corrugations being aligned in parallel relation to an opposed pair of said alternate edges provided with locking recesses, the corrugations of the end cap and the pad thus being biased in respect to each other.

5. A heavy duty bulk container as in claim 4, wherein the free end edge of double thickness flange inner ply is diminished in width in respect to the said inner and outer ply fold connection.

6. A heavy duty bulk container as in claim 4, wherein adhesive is applied between the inner surface of at least one wall flange and the adjacent tubular sleeve wall panel whereby the interlocking, fixed disposition of the closure assembly wall flanges sustain the disposition until the adhesive sets.

7. A heavy duty bulk container as in claim 4, wherein a plurality of pallet runners are adhesively secured to the outer surface of the end cap central panel in parallel spaced apart relation, said pallet runners being disposed parallel to an opposed pair of double thickness wal-l flanges and the corrugations of the end cap be biased in respect to the pallet runners affording rigidity in spanning the space between said runners.

References Cited by the Examiner UNITED STATES PATENTS 1,451,963 4/1923 Scruby. 2,003,326 6/ 1935 Wellman. 2,307,076 1/ 1943 Ray. 2,818,972 1/1958 Claus. 3,122,298 2/1964 Seger.

FOREIGN PATENTS 1,320,926 4/1963 France.

JOSEPH R. LECLAIR, Primary Examiner. D. T. MOORHEAD, Assistant Examiner. 

1. A BULK CONTAINER COMPRISING AN UPSTANDING TUBULAR SLEEVE AND A CLOSURE ASSEMBLY DISPOSED IN TELESCOPING RELATION OVER ONE END THEREOF; THE TUBULAR SLEEVE COMPRISING A PLURALITY OF FOLDABLY CONNECTED WALL PANELS INCLUDING AT LEAST THREE PAIR OF PANELS IN RESPECTIVE OPPOSED, PARALLEL RELATION AND WITH TOP AND BOTTOM EDGES; THE CLOSURE ASSEMBLY COMPRISING AN END CAP AND LOCKING REINFORCING PAD; THE END CAP INCLUDING A CENTRAL CLOSURE PANEL COEXTENSIVE WITH THE TUBULAR SLEEVE END EDGE CONFORMATION; A PLURALITY OF WALL FLANGES, CORRESPONDING IN NUMBER TO THE SLEEVE WALL PANELS, AND HINGEDLY CONNECTED TO SIDE EDGES OF THE CENTRAL CLOSURE PANEL; THE WALL FLANGES INCLUDING ALTERNATING SINGLE AND DOUBLE THICKNESS PANELS; AND EXTENSION OF THE SINGLE THICKNESS FLANGES FIXEDLY SESURED BETWEEN INNER AND OUTER PLIES OF THE DOUBLE THICKNESS FLANGE; THE REINFORCING PAD BEING IN FLATWISE SUBSTANTIALLY COEXTENSIVE RELATION TO THE END CAP CENTRAL CLOSURE PANEL AND HAVING ALTERNATE RECESSED EDGES ADAPTED TO RECEIVE FREE END EDGES OF THE DOUBLE THICKNESS FLANGE INNER PLY THUS SECURING THE REINFORCING PANEL IN FIXED RELATION TO THE END CAP CENTRAL PANEL AND THE WALL FLANGES TO EACH OTHER AND IN RIGHT ANGULAR RELATION TO THE CENTRAL CLOSURE PANEL. 